# Chapter 4: Abstract Data Types

- [x] [4.1 ▷](./ex.4.1.cpp)
- [x] [4.2](./ex.4.2.cpp)
- [x] [4.3 ○](./ex.4.3.cpp)
- [x] [4.4 ○](./ex.4.4.cpp)
- [ ] 4.5 ●●
- [x] [4.6 ▷](./ex.4.6.cpp)
- [x] [4.7 ▷](./ex.4.7.cpp)
- [ ] 4.8
- [x] [4.9 ▷](./ex.4.9.md)
- [x] [4.10](./ex.4.10.md)
- [x] [4.11 ●●](./ex.4.11.cpp)
- [x] [4.12 ▷](./ex.4.12.md)
- [x] [4.13 ▷](./ex.4.13.md)
- [x] [4.14 ▷](./ex.4.14.cpp)
- [x] [4.15](./ex.4.15.cpp)
- [x] [4.16](./ex.4.16.md)
- [ ] 4.17 ●
- [x] [4.18 ○](./ex.4.18.cpp)
- [ ] 4.19 ○
- [x] [4.20 ●●](./ex.4.20.cpp)
- [x] [4.21 ▷](./ex.4.21.md)
- [ ] 4.22 ○
- [ ] 4.23
- [ ] 4.24
- [x] [4.25](./ex.4.25.cpp)
- [ ] 4.26
- [x] [4.27 ●](./ex.4.27.cpp)
- [ ] 4.28 ●
- [x] [4.29](./ex.4.29.h)
- [x] [4.30](./ex.4.30.h)
- [ ] 4.31 ○
- [x] [4.32](./ex.4.32.h)
- [ ] 4.33 ○
- [ ] 4.34 ○
- [ ] 4.35 ●
- [x] [4.36 ▷](./ex.4.36.md)
- [x] [4.37 ▷](./ex.4.37.md)
- [x] [4.38](./ex.4.38.cpp)
- [x] [4.39](./ex.4.39.cpp)
- [x] [4.40 ▷](./ex.4.40.md)
- [x] [4.41 ▷](./ex.4.41.md)
- [x] [4.42 ●](./ex.4.42.cpp)
- [x] [4.43 ▷](./ex.4.43.h)
- [x] [4.44](./ex.4.44.cpp)
- [x] [4.45](./ex.4.45.cpp)
- [ ] 4.46
- [x] [4.47](./ex.4.47.cpp)
- [x] [4.48 ○](./ex.4.48.cpp)
- [ ] 4.49 ●●
- [x] [4.50 ▷](./ex.4.50.cpp)
- [x] [4.51](./ex.4.51.cpp)
- [ ] 4.52 ●
- [x] [4.53 ▷](./ex.4.53.md)
- [x] [4.54](./ex.4.54.cpp)
- [x] [4.55](./ex.4.55.cpp)
- [x] [4.56 ●](./ex.4.56.cpp)
- [ ] 4.57 ○
- [x] [4.58](./ex.4.58.cpp)
- [x] [4.59](./ex.4.59.cpp)
- [ ] 4.60
- [x] [4.61](./ex.4.61.cpp)
- [ ] 4.62
- [x] [4.63 ▷](./ex.4.63.cpp)
- [x] [4.64](./ex.4.64.cpp)
- [ ] 4.65
- [x] [4.66 ●●](./ex.4.66.md)
- [ ] 4.67 ○
- [ ] 4.68 ●
- [ ] 4.69
- [x] [4.70 ●](./ex.4.70.cpp)
- [ ] 4.71 ▷
- [ ] 4.72
- [x] [4.73 ▷](./ex.4.73.h)
- [x] [4.74](./ex.4.74.cpp)
- [x] [4.75](./ex.4.75.cpp)
- [ ] 4.76 ○
- [ ] 4.77 ●●
- [x] [4.78 ○](./ex.4.78.cpp)
- [x] [4.79 ○](./ex.4.79.cpp)
- [x] [4.80 ▷](./ex.4.80.cpp)
- [x] [4.81 ○](./ex.4.81.cpp)
- [ ] 4.82
- [x] [4.83 ●●](./ex.4.83.cpp)
- [x] [4.84 ●](./ex.4.84.cpp)
- [ ] 4.85 ●
- [ ] 4.86 ●●
- [ ] 4.87
- [ ] 4.88
- [ ] 4.89
- [ ] 4.90
- [ ] 4.91
- [ ] 4.92
- [ ] 4.93
